refactor: extract ToCString trait into separate crate

[wangl-cc]

Summary by Sourcery

引入共享的 FFI 字符串工具 crate，将触摸与任务类型重构到独立模块并增加客户端类型支持，同时更新绑定和错误处理以使用新的抽象。

Enhancements:

• 新增 maa-ffi-string crate，用于集中管理安全的 CString 转换，并在 FFI 边界间复用。
• 将 TouchMode 和 TaskType 定义重构到单独的 maa-types 模块中，并通过 crate 根对外暴露，同时添加 schema、serde、clap 和 FFI 集成钩子。
• 新增 ClientType 枚举，支持解析、序列化、clap 集成，以及用于包、资源和服务器元数据的辅助方法。
• 简化 maa-sys 的 FFI 绑定，复用 std::ffi 中的 c_char / c_void 别名，并更新错误类型，以区分无效参数和无效返回值。

Build:

• 将 maa-ffi-string 添加为 workspace crate，并接入 maa-sys 和 maa-types 的依赖中，相应提升 crate 版本并启用新的 feature flags。
• 为 maa-types 新增可选的 clap、maa-ffi-string、schemars 和 serde feature flags，以支持 CLI、FFI 和 schema。

Original summary in English

Summary by Sourcery

Introduce a shared FFI string utility crate, refactor touch and task types into dedicated modules with additional client type support, and update bindings and error handling to use the new abstractions.

Enhancements:

• Add the maa-ffi-string crate to centralize safe CString conversion and reuse across FFI boundaries.
• Refactor TouchMode and TaskType definitions into separate maa-types modules and expose them via the crate root, adding schema, serde, clap, and FFI integration hooks.
• Introduce a ClientType enum with parsing, serialization, clap integration, and helper methods for package, resources, and server metadata.
• Simplify maa-sys FFI bindings by reusing std::ffi c_char/c_void aliases and updating error types to distinguish invalid arguments from invalid return values.

Build:

• Add maa-ffi-string as a workspace crate and wire it into maa-sys and maa-types dependencies, bumping crate versions accordingly and enabling new feature flags.
• Add optional clap, maa-ffi-string, schemars, and serde feature flags to maa-types for CLI, FFI, and schema support.

[sourcery-ai]

Hey - 我发现了 3 个问题，并给出了一些整体反馈：

• enum 辅助方法（COUNT/NAMES/VARIANTS、from_u8/from_str_opt、unsafe transmute）现在在 ClientType、TaskType 和 TouchMode 中都有重复；可以考虑把它们提取到一个小的宏或共享工具里，以减少重复，并把不安全的模式集中管理。
• ClientType 的 serde 实现只支持从字符串反序列化，但序列化时却用的是 u64，这在行为上是不对称的；如果这不是刻意设计的，建议要么像 TaskType/TouchMode 那样也支持数字反序列化，要么改成序列化为字符串，以与预期的输入格式保持一致。

给 AI Agent 的提示

Please address the comments from this code review:

## Overall Comments
- The enum helpers (COUNT/NAMES/VARIANTS, from_u8/from_str_opt, unsafe transmute) are now duplicated across ClientType, TaskType, and TouchMode; consider extracting this into a small macro or shared utility to reduce repetition and keep the unsafe pattern centralized.
- ClientType’s serde implementation deserializes only from string but serializes as a u64, which is asymmetric; if not intentional, consider either supporting numeric deserialization as well (like TaskType/TouchMode) or serializing as a string to match the expected input format.

## Individual Comments

### Comment 1
<location> `crates/maa-types/src/client_type.rs:140-149` </location>
<code_context>
+
+impl std::error::Error for UnknownClientTypeError {}
+
+#[cfg(feature = "serde")]
+impl<'de> serde::Deserialize<'de> for ClientType {
+    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        struct ClientTypeVisitor;
+
+        impl serde::de::Visitor<'_> for ClientTypeVisitor {
+            type Value = ClientType;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a valid client type")
+            }
+
+            fn visit_str<E: serde::de::Error>(self, value: &str) -> Result<Self::Value, E> {
+                ClientType::from_str_opt(value)
+                    .ok_or_else(|| E::unknown_variant(value, &ClientType::NAMES))
+            }
+        }
+
+        deserializer.deserialize_str(ClientTypeVisitor)
+    }
+}
</code_context>

<issue_to_address>
**issue (bug_risk):** ClientType 以数字形式序列化，但仅从字符串反序列化，导致 serde 的往返兼容性被破坏。

`ClientType` 通过 `serializer.serialize_u64(*self as u64)` 来序列化，但反序列化则通过 `deserialize_str`，且只实现了 `visit_str`。因此由 `Serialize` 产生的值在反序列化时会因 "invalid type: integer ..." 错误而失败。

为了恢复往返兼容性并与 `TaskType`/`TouchMode` 保持一致，可以：
- 把 `Serialize` 改为输出字符串（例如 `serializer.serialize_str(self.to_str())`），或者
- 扩展 visitor 以处理数值输入（例如实现 `visit_u64`，并使用 `deserializer.deserialize_any(ClientTypeVisitor)` 或类似的入口，让整数 token 被路由到 `visit_u64`）。
</issue_to_address>

### Comment 2
<location> `crates/maa-types/src/task_type.rs:151` </location>
<code_context>
-            }
-        }
-
-        deserializer.deserialize_str(TaskTypeVisitor)
-    }
-}
</code_context>

<issue_to_address>
**issue (bug_risk):** TaskType 的反序列化器声明为 `deserialize_str`，却试图通过 `visit_u64` 处理整数，在当前配置下 serde 永远不会调用它。

由于入口是 `deserializer.deserialize_str(TaskTypeVisitor)`，serde 在处理数值输入时永远不会调用 `visit_u64`；整数 token 会在到达 visitor 之前就报错。因此用于处理整数的分支实际上是死代码，从 `u64` 反序列化也就无法按预期工作。

为了同时支持字符串和整数表示（并与 `Serialize` 实现保持一致），可以把入口改成类似 `deserializer.deserialize_any(TaskTypeVisitor)` 的形式（或者使用一个包装器，依次尝试 `deserialize_u64` 和 `deserialize_str`），这样数值 token 才能真正被路由到 `visit_u64`。
</issue_to_address>

### Comment 3
<location> `crates/maa-types/src/touch_mode.rs:137` </location>
<code_context>
-            }
-        }
-
-        deserializer.deserialize_str(TouchModeVisitor)
-    }
-}
</code_context>

<issue_to_address>
**issue (bug_risk):** TouchMode 的反序列化器同样无法真正消费数值 token，尽管实现了 `visit_u64`。

`TouchModeVisitor` 实现了 `visit_u64`，但 `Deserialize` 使用的是 `deserializer.deserialize_str(TouchModeVisitor)`，所以整数 token 永远不会到达 `visit_u64`。这很可能会破坏与 `Serialize` 实现（输出 `u64`）之间的往返行为。

为了启用数值分支并仍然支持字符串，应切换为 `deserializer.deserialize_any(TouchModeVisitor)`（或其他可以接受字符串和整数 token 的入口）。
</issue_to_address>

---

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Original comment in English

Hey - I've found 3 issues, and left some high level feedback:

• The enum helpers (COUNT/NAMES/VARIANTS, from_u8/from_str_opt, unsafe transmute) are now duplicated across ClientType, TaskType, and TouchMode; consider extracting this into a small macro or shared utility to reduce repetition and keep the unsafe pattern centralized.
• ClientType’s serde implementation deserializes only from string but serializes as a u64, which is asymmetric; if not intentional, consider either supporting numeric deserialization as well (like TaskType/TouchMode) or serializing as a string to match the expected input format.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- The enum helpers (COUNT/NAMES/VARIANTS, from_u8/from_str_opt, unsafe transmute) are now duplicated across ClientType, TaskType, and TouchMode; consider extracting this into a small macro or shared utility to reduce repetition and keep the unsafe pattern centralized.
- ClientType’s serde implementation deserializes only from string but serializes as a u64, which is asymmetric; if not intentional, consider either supporting numeric deserialization as well (like TaskType/TouchMode) or serializing as a string to match the expected input format.

## Individual Comments

### Comment 1
<location> `crates/maa-types/src/client_type.rs:140-149` </location>
<code_context>
+
+impl std::error::Error for UnknownClientTypeError {}
+
+#[cfg(feature = "serde")]
+impl<'de> serde::Deserialize<'de> for ClientType {
+    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        struct ClientTypeVisitor;
+
+        impl serde::de::Visitor<'_> for ClientTypeVisitor {
+            type Value = ClientType;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a valid client type")
+            }
+
+            fn visit_str<E: serde::de::Error>(self, value: &str) -> Result<Self::Value, E> {
+                ClientType::from_str_opt(value)
+                    .ok_or_else(|| E::unknown_variant(value, &ClientType::NAMES))
+            }
+        }
+
+        deserializer.deserialize_str(ClientTypeVisitor)
+    }
+}
</code_context>

<issue_to_address>
**issue (bug_risk):** ClientType serializes as a number but only deserializes from a string, breaking round‑trip serde compatibility.

`ClientType` is serialized via `serializer.serialize_u64(*self as u64)` but deserialized via `deserialize_str` with only `visit_str` implemented. A value produced by `Serialize` will therefore fail to deserialize with an "invalid type: integer ..." error.

To restore round‑trip compatibility and match `TaskType`/`TouchMode`, either:
- change `Serialize` to output a string (e.g. `serializer.serialize_str(self.to_str())`), or
- extend the visitor to handle numeric input (e.g. implement `visit_u64` and use `deserializer.deserialize_any(ClientTypeVisitor)` or a similar entry point that routes integers to `visit_u64`).
</issue_to_address>

### Comment 2
<location> `crates/maa-types/src/task_type.rs:151` </location>
<code_context>
-            }
-        }
-
-        deserializer.deserialize_str(TaskTypeVisitor)
-    }
-}
</code_context>

<issue_to_address>
**issue (bug_risk):** TaskType deserializer is declared as `deserialize_str` but tries to handle integers via `visit_u64`, which serde will never call in this configuration.

Because the entry point is `deserializer.deserialize_str(TaskTypeVisitor)`, serde will never call `visit_u64` for numeric input; integer tokens will error out before reaching the visitor. So the integer-handling branch is effectively dead and deserialization from `u64` won’t work as intended.

To support both string and integer representations (and match the `Serialize` implementation), change the entry point to something like `deserializer.deserialize_any(TaskTypeVisitor)` (or use a wrapper that tries both `deserialize_u64` and `deserialize_str`) so numeric tokens are actually routed to `visit_u64`.
</issue_to_address>

### Comment 3
<location> `crates/maa-types/src/touch_mode.rs:137` </location>
<code_context>
-            }
-        }
-
-        deserializer.deserialize_str(TouchModeVisitor)
-    }
-}
</code_context>

<issue_to_address>
**issue (bug_risk):** TouchMode deserializer similarly cannot actually consume numeric tokens despite implementing `visit_u64`.

`TouchModeVisitor` implements `visit_u64`, but `Deserialize` uses `deserializer.deserialize_str(TouchModeVisitor)`, so integer tokens never reach `visit_u64`. This likely breaks round-tripping with the `Serialize` impl, which emits `u64`.

To use the numeric branch and still support strings, switch to `deserializer.deserialize_any(TouchModeVisitor)` (or another entry point that accepts both string and integer tokens).
</issue_to_address>

---

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